This means that, instead of generating machine code for every architecture to be supported, compilers for those languages just generate intermediate C code, and the C compiler handles the machine code generation. C has also become a lingua franca for communicating between developers.
C is a great language for expressing common ideas in programming in a way that most people are comfortable with. Arbitrary memory address access and pointer arithmetic is an important feature that makes C a perfect fit for system programming operating systems and embedded systems. System applications must read and write to those custom memory locations to communicate with the world.
In other words: write the value of variable byte to memory address 0x In this line, we perform a bitwise OR operation on the value at address 0x and the value 0x08 in binary, i. In other words: we set bit 4 of the byte that is at address 0x We also declare that the value at address 0x is volatile.
In this case, this bit is unset by the UART hardware just after we set it by software. If we did this inside a for loop, for example, without specifying that the value is volatile, the compiler might assume this value never changes after being set, and skip executing the command after the first loop.
A common language feature that system programming cannot rely on is garbage collection, or even just dynamic allocation for some embedded systems. Embedded applications are very limited in time and memory resources. They are often used for real-time systems , where a non-deterministic call to the garbage collector cannot be afforded.
And if dynamic allocation cannot be used because of the lack of memory, it is very important to have other mechanisms of memory management, like placing data in custom addresses, as C pointers allow. C has a very small runtime. And the memory footprint for its code is smaller than for most other languages. One of the main causes for that is exceptions support. Methods of A , B and C classes are defined somewhere else for example in other files.
Therefore the compiler cannot analyze them and cannot know if they will throw exceptions. So it must prepare to handle exceptions thrown from any of their constructors, destructors, or other method calls. Destructors should not throw very bad practice , but the user could throw anyway, or they could throw indirectly by calling some function or method explicitly or implicitly that throws an exception.
If any of the calls in myFunction throw an exception, the stack unwinding mechanism must be able to call all the destructors for the objects that were already constructed. It does this by making use of an auxiliary autogenerated function a kind of look-up table that will be used for stack unwinding in case an exception is thrown from the body of that function, which will be similar to this:.
If the exception is thrown from checkpoints 1 and 9, no object needs destruction. For checkpoint 3, b and a must be destructed. For checkpoint 6, c and a must be destructed. In all cases the destruction order must be respected. For checkpoints 2, 4, 5, 7, and 8, only object a needs to be destructed. This auxiliary function adds size to the code.
Many embedded applications cannot afford this extra space. While C does not give you the use of these extra features, it allows a much more compact code footprint than the other languages. Find threads, tags, and users I was thinking this question from a long time. Comment Show 0. Current Visibility: Visible to all users. My guess about Windows 10 is written in C. Would you really like to know about Windows 1. If you find a response give us a link please I want to be sure about my conclusion :p — Mabrouki Fakhri.
CRT functions like longjmp, calloc, free indicate C code, might well be ancient and hark back to the command. It is unlikely that cmd. Show 4 more comments. Active Oldest Votes. Community Bot 1 1 1 silver badge. CodeCaster CodeCaster k 19 19 gold badges silver badges bronze badges. Add a comment.
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Email Required, but never shown. There is simply no compelling reason to replace it. It will remain one of the dominant IT languages for decades.
Java, however, is not recommended for beginners as it is a more complex program. Python is more forgiving as you can take shortcuts such as reusing an old variable. Additionally, many users find Python easier to read and understand than Java.
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